Hotchkiss



Dec. 16, 1941. c. HoTcHKlss ELECTRICALLY OPERATED HEATER CONTROL Original Filed April 28, 1932 6 Shee'ts-Sheet l ,4free/VE Yr Q/FFoeo//oTcH/f/Js Dec. 16, 1941. c. Ho'rcHKlss ELECTRICALLY OPERATED HEATER CONTROL 1952 6 Sheets-Sheet 2 Original Filed April 28 fz Ver@ 010 CL /FFo/eo #OTC/#05s ATTacA/EYJ Dec. 16, 1941. c. HoTcHKlss Re 21,977

ELECTRICALLY OPERATED HEATER CONTROL s sheets-sheet s f 7a4/e721?! o2" C2 /FFoeo Hora/Kms Dec. 16, 1941. c. HoTcHKlss ELECTRICALLY OFERATED HEATER CONTROL 1952 6 Sheets-Sheet 4 Original Filed April 28 ATTO/@VE Yo* DCC 16 1941 c. HoTcHKlss Re. 21,977

ELECTRICALLY OPERATED HEATER CONTROL Original Filed April 28, 1932 6 Sheets-Sheet 5 jM--JF-J MM TTQENEYJ Dec. 16, 1941. c. HoTcHKlss Re- 21,977

ELECTRIGALLY OPERATED HEATER CONTROL Original Filed April 28, 1952 6 Sheets-Sheet 6 /60 E ZIO /64 Zoff /as-QQQQU zum) Ffa/5 jm/emgo C L /FFoeo /JbTcHK/ss Z521 Y fd l nu! itl/m Ressued Dec. 16, 1941 UNITED STATES PATENT OFFICE ELECTBICAILY OPEBATED HEATER CONTROL Cli'ord Hotchkiss, Milwaukee, Wis., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation ol' Delaware Ol'lglnal No. 2,169,696, dated August 15, 1939, Serial No. 608,008, April 28, 1932. Renewed February `3, 1938.

Applicat `for reissue Meren 7, 1340, serial No. 322,86 s

(cl. zasl) 35 Claims.

This invention pertains to electrically operated heater controls and relates more particularly to heat supply control valves. Such valves may be of the type located in the fuel supply line, may constitute dampers in the heater ilues, or may be any desired type of valves for controlling the supply oi' heat by a heater to a given space.

In automatic heating systems it is customary magnet to position the valve so as to cause the heater to supply a maximum .amount ol' heat and the arrangement is such that when the valve is open, the motor will be de-energized but the electro-magnet will be energized and will be operative to maintain the valve in open position. Upon the occurrence of a power failure the electromagnet will of course become deenergized and to provide a thermally responsive device such as Will permit the Valve t0 move to its minimum a bimetailic thermostat in the space to be heated, l0 heat supply position under the inlluence oi either and associate with such thermostat means for gravity or any desired type of biasing means operating the heater controls. Since these conwhich may be provided. Thus, the motor does trols are ordinarily removed from the space to not consume any current while the valve is being be heated and since the bimetallic thermostat is maintained in open position. The only Current a relatively delicate instrument with little power, expended in order to hold the valve open is that the means for operating the remotely located consumed in the electro-magnet. F1111 Safety heater controls are ordinarily electrical rather upon the occurrence of power failure results and than mechanical in nature and for purposes of there is a minimum expenditure of power during safety, means must be provided for automatically Operation.

placing the heat controls in minimum heat sup- Again, itis an object of the invention to provide ply position, i. e. closed position, upon the occura simplled and dependable System embodying rence of power failure. If such means were not the feature discussed above.

provided it will be readily appreciated that the Where the heat supply control valve comprises heater might become too hot and reach a dangera valve in the gas supply line 0f a ges heater. iii ous temperature. is sometimes desirable to elect a quick closing o! It has heretofore been the practice in autothe valve and is sometimes desirable to effect a matic heat control systems ot the type discussed SlOW Closing thereof, depending Upon the particuabove to bias the heat control member to a posilar type of burner or heater which the valve is tion in which it will cause the heater to supply a Controlling. It is a speCiC Object 0f the Present minimum amount of heat, and to move the meminvention to provide a. control system embodying ber away from such minimum heat supply posithe features discussed above, and which can also tion to a maximum heat supply position by be selectively arranged to close the gas supply means of an electric motor, of any desired type, valve either quickly or slowly when the room such as the conventional rotary or the solenoid thermostat indicates that the Space t0 be heated type, which remains stalled in order to hold the has reached the desired temperature. heat control member in its maximum heat sup- It is an additional object of the invention to ply position. It is obvious that on appreciable provide a heat control system wherein the heat waste of power occurs as a result or so holding control valve closes automatically upon power the heat control member in maximum heat supfailure but wherein the control 0f this Valve by ply position. Also, the stalled motors become the room thermostat is resumed automatically unduly heated during the holding period. upon the resumptionl of POWel'.

It is a general purpose of the present invention Still another object of the invention lies in the to provide an automatic heat control system provision 0f 8 heat CODIOI System wherein the wherein the heat control member is automatically heat COIltlOl Valve may be opened manlllly after returned to position m which it causes the heat-,e1- 45 power failure and wherein the control oi' the valve to supply a minimum amount of heat upon power will beg automatically taken rover by the room failure, but wherein it is not necessary to stan the thermostat upon the resumption of power. irreoperating motor in order to-maintain. the heat spectlve ol.' the fact that the valve has been control member in maximum heat supply position. manually Opened- In accordance with the invention there is prol0 'I'he various features and objects of the invenvided ar motor under the control of the room thermostat for supplying the necessary power to move the valve away from its position in which it causes the heater to supply a minimum amount of heat. This motor cooperates with an electrotion will become more readily apparent upon a.

detailed study of the accompanying drawings and' specification together with the appended claims. The drawings are merely illustrative of the invention and disclose the same as applied to a Cil Figure 2 is a view similar to Figure 1 but showing the parts when the valve is open under normal conditions of operation.

Figure 3 is a cross section along line 3 3 of Figure l;

Figure 4 is a view along line 4 4 ofFigure l;

Figure 5 is a View along line 5 5 of Figure 3;

Figure 6 is a view along line 6 6 of Figure 3;

Figure 7 is a front view of the panel for the electrical contacts showing the positions of the parts when the valve is closed under normal conditions of operation and also showing the internal wiring of the instrument;

Figure 8 ls a fragmentary view showing the positions of the contacts when the valve is open under normal conditions of operation;

Figure 9 is a similar view showing the positions of the parts when power failure has occurred after the motor has positioned the operating cam to open the valve, and the valve has been manually opened;

Figure 10 is likewise a similar view showing the positions of the contacts after the valve is manually opened following power failure which occurred while the motor was positioned to allow the valve to close;

Figure 11 is a view diagrammatically showing the invention applied to a heating system including a gas-red hot air furnace;

Figure 12 is a system diagram showing the Wiring of the control circuit where a double contact thermostat is used, and where it is desired to cause the valve to close slowly when desired room temperature is reached;

Figure 13 is another system diagram showing a two-wire thermostat and connections operative to cause the valve to close quickly upon the reaching of predetermined room temperature;

Figure 14 shows the circuit of the hot air circulating fan; and

Figure 15 is a fragmentary diagrammatic view of a modied form of control circuit.

Referring to the drawings, the numeral 2 designates a gas-fired hot air heater having a gas supply line 4, in which i's a valve generally designated at 6. A room thermostat indicated at 8 controls the valve 6 to regulate the supply of gas to the heater 2 and a warm air circulating fan 9 is placedin operation only'while the valve 6 is opened to supply gas to the heater. A secondary air damper I0 controls the flow of air to the combustion chamber and is adapted to be open only when the valve 6 is open and vice versa since it is undesirable to circulate cold air through the combustion chamber when combustion is not taking place. The heater 2 is adapted to supply heat to a space I2 in which the room thermostat 8 is situated, all as shown in Figure 11.

Upon more particular reference to Figures l to 6, it will be seen that the valve 6 is provided with a casing I4 which forms an inlet chamber I6 and an outlet chamber I8 separated by a walll 20 having an opening therein provided with a seat for the valve member 22. The valve member 22 has attached thereto a stem 24 which passes upwardly out of the valve casing I4 and into a. casing generally designated at 26 which houses the mechanism for positioning the valve member 22.

I'he casing 26 is mounted above an annular support 28 which is xed on top of the valve casing I4 and the usual means are provided for sealing the outlet vchamber I8 of the valve casing. The valve is normally -biased into closed position by means of the compression spring 38 as shown in Figure 1.

Casing 26 has a" base portion 32 upon which are supported in upright position a pair of parallel longitudinally extending metallic plates 34 and 36. The plates 34 and 36 are secured to upwardly extending portions 38 and 40 which are formed integrally with the base 32, by means of suitable screws or bolts as shown. An electric motor 42 of the low voltage induction type is mounted on the side of the plate 36 and has an armature mounted on a motor shaft 44 which extends between the plates 34 and 36. The motor shaft 44 has fixed thereon a gear 46 which operates a gear train having at one end the gear wheel 48. This gear wheel 48 has xed on one face thereof an eccentric or cam member 56 and is mounted upon a shaft 52.

An electro-magnet generally designated at 54 is pivoted upn a shaft 56 which is secured between the two metallic plates 34 and 36. This electro-magnet has an energizing coil 58 and a core 60 to which is xed a depending arm 62 that is in the shape of a bell-crank lever. An armature 64 is pivoted to the electro-magnet as at 66 and is held adjacent the core 6l) as shown in the full line positions in Figures l and 2 when the coil 53 is energized. A link 68 is pivoted at one end to the armature 64 and is pivotally connected at its other end to a pin 10 which is mounted transversely in a coupling member I2 having a threaded socket engaged by the upper threaded end of valve stem 24. The pin III is formed with reduced end portions which operate in oppositely disposed slots 14 formed in the metallic walls 34 and 36. One of these reduced end portions extends outside of the wall 34 for a purpose to be later described. The slots 'I4 are vertical and of just suilicient width to accommodate the reduced portions of the pin 10 and therefore serve as guides for the same.

The arm 62 which is fixed to the electro-magnet 54 has fixed thereto at one side a roller 'I6 lying in the path of the cam 53 and also has xed thereto another roller 18 which is adapted to engage one arm of bell-crank lever 86 ilxed on shaft 82. A spring 84 has one end secured to the other arm of bell-crank lever B0 and has its other end secured to a post 86 which is mounted between the metallic plates 34 and 36.

When the various parts are in the position shown in Figure 1, the valve is closed, the cam 50 is out of engagement with the roller 16 on the arm 62 of electro-magnet 54. and the bell-crank lever 8U is exerting a downward force upon the roller I8 under the tension of spring 84. This force tends to rotate the electro-magnet 54 in counter-clockwise direction, and thus serves to urge the electro-magnet and valve into down position, in which position the armature 641s mechanically held in engagement with electro-magnet 54 due to the proportions and relative positions of the various parts. If the motor is started and operated sufficiently to move cam 5I) into the position shown in Figure 2, the cam will engage roller 16 and rotate the electro-magnet 54 in clockwise direction thereby to raise its outer end to which the armature 64 is pivoted. Assuming that the coil 58 was energized during this movement of the cam. the armature 84 will remain in engagement with the core 88 and the parts will assume the relative positions shown in full lines in Figure 2. It will be noted that in this position the valve is fully open and cam 80 is on dead center with the result that the springs 30 and 84 cannot operate to return the valve and electro-magnet to the positions shown in Figure l even though no brake or other means for holding the motor against rotation are provided. During such rotation of arm 82 in clockwise direction and consequent opening of the valve, it will be observed that the shaft 82 will be simultaneously rotated in counter-clock-wise direction due to engagement of the bell-crank lever 80 by the roller 18.

If failure of the power source occurs when the parts are in the full line position shown in Figure 2, the cam 50 and electro-magnet 54 will not move. However, the armature 84 will be released from the core 80 and the valve member 22 will be moved into closed position under the influence of spring 30,1the parts assuming the positions illustrated in dotted lines in Figure 2. It is to be noted that the electro-magnet 84 is not sunlciently strong when energized to attract the armature to it from the dotted line position shown in Figure 2. However, the magnet is sumciently strong when energized to retain the armature adjacent itself during movement of the valve from position shown in Figure 1 to that shown in Figure 2. If the parts are in the posi tions shown in dotted lines in Figure 2, and the motor is thereupon operated to move the cam 80 and electro-magnet 54 back to their positions shown in Figure 1, the armature 84 will be mechanically moved back into engagement with core 80 independently of whatever force the magnet I."4 may exert upon the armature 84 when they are separated.

The shaft 52 of the gear wheel 48 extends through an opening in the metallic plate 84 and further extends through an opening in a panel board 88 of suitable insulating material. 'I'he end of shaft 52 which extends through the opening in the panel board 88 is reduced and has fixed thereto a pair of cams 80 and 82 as shown more clearly in Figures 4 and 7 to 10, inclusive. 'I'he cam member 80 has oppositely disposed concentric outer edges 84 which are separated by a pair of notches or recesses situated 180 apart. Cam 82 is of the simple type formed with a single oilcenter projection which is located at substantially the same distance from the center of shaft 52 as the outer concentric surfaces 84 of the cam 90. It is to be noted that this projection of cam 82 is co-incident with one of the notches in cam member 90 as will be evident from Figure 4.

An arm 98 is pivoted upon post |00 which is secured to the panel board 88 and has formed integrally at its outer end a cross piece |02 which is adapted to ride on the outer edge of cammember 80. The arm 88 is actuated towards cam member 90 under the tension of a spring |04 that is wrapped'around post |00. A contact |08 is flexibly mounted upon the arm 88 and cooperates with a fixed contact |08 on the post ||0. When the cross piece |02 of the rigid arm 88 lies in the notch of the cam member 88, which is remote from the projection of cam member 82, the contact |06 is separated from the contact |08 but when the cross piece |02 rides on one of the concentric edge suriaces 94, the contacts |08 and |06 engage. So also, the contacts |08 and |08 are in engagement when the cross piece |02 is v 3 engagedbythecamlaswillbeevidentfrom Figuresand. Asimilararmlllisplvotally mounted upon the pin |'I4 and has its free end actuated Vto ride on the .outer edge' of cam member 88 by meansofaspring Ill. Thisarm ||2 has flexibly mounted thereon a contact ||8 which cooperates with a nxedcontact |28 on the post |22. When thefreeendoi' arm ||2 islocatedin one of the notches or recesses of cam member 88, contacts III and |28 are out of engagement but when this arm rides on one of the concentric surfaces 84, contacts ||8 and |28 are moved into engagement. Pivoted o n the pin ||4 there is also an arm |24 whose free end is actuated to ride against the outer edge of cam member 82 by a spring |28 coiled about pin |'|4. This arm |24 has flexibly secured thereto a contact |28 which engages the fixed contact when the parts are in the position shown in Figure 7 and which ensages the xed contact` |32 when cam member 82 is moved 180 as shown in Figures 8 and 8. The cams 80-82 rotate 180 upon movement of the parts from the position shown in Figure l to that shown in Figure 2.

Means are provided for manually setting the valve in open position if the source of power fails for any reason. These means include a shaft |34 which extends outside of the case 28 and is provided with a handle |38. The shaft extends between the metallic plates 34 and 38 and has fixed at its end a lever |38 having a cam surface |40 and a notched end as indicated at |42 (see Figure 5). When the shaft |34 is rotated in clock-wise direction, looking at Figure 5. the cam surface |48 engages the pin 10 thereby to raise the same together with the valve stem 24 and the valve member 22. Continued rotation of the shaft |84 in clock-wise direction results in a seating of the pin 10 in the notched portion |42. When this occurs the parts retain themselves in the dotted line positions shown in Figure 5 and the valve is partially open. The valve can be closed by manually rotating the shaft |34 in counter-clock-wise direction to disengage the lever |38 from the pin '|0.

It is to be noted that the shaft |34 is normally urged into the full line position shown in Figure 5 by the spring |'44 and that the valve is only partially open and the free end of the electromagnet 54 is only partially raised when the lever |38 is in the dotted line position shown in Figure 5. If the electro-magnet 54 is therefore raised to a point above the dotted line position shown in Figure 5, i. e. to the full line position shown in Figure 2, while the amature 84 is held thereby, it is obvious that the pin 'I0 will be moved up suillciently far to release lever |38 whereupon the shaft |34 and lever |38 will be returned to full line position shown in Figure 5 under the action of spring |44. Thus the means for manually setting the valve in open position will be automaticallyreleased upon va raising of the valve to full open position by the motor and electromagnet.

Whenever the pin 18 is raised. either upon opening of the valve by means of the motor in normal operation or upon a manually opening of the valve by means of'handle |38, as Just described. it engages a lever |48 which is ilxed on a shaft |48 extending to the outside of the panel board 88 where it has fixed thereto an arm |80. On this arm is flexibly mounted a contact |82 cooperating with a fixed contact |84 carried by the post |22. The shaft |48 is tensioned by a spring so that it causes contacts |82 and |84 to remain in engagement except when the lever |46 is raised by means of the pin 10. The shai't |34 has secured thereto a cam |56 which engages one arm of a rigid bell-crank lever |58 pivoted on the outside of the panel 88 at |60 and formed with a contact |62 on its other arm. A spring tate lever ||2 into position to cause contacts 8 and to engage.

The various contacts assume the positions indicated in Figure 'l when the cam 50 is positioned as shown in Figure 1 and the valve is closed as also shown therein. When the motor has rotated gear wheel 48 sufficiently to move the valve into open position by means of cam 50, as shown in full lines in Figure 2. the contacts will assume the relative positions shown in Figure 8. However, if the parts are in the positions shown in Figures. 2 and 8 and a power failure occurs followed by a manual opening of the valve, the contacts will assume the relative positions shown in Figure 9. If a power failure occurs while the valve is closed and the gear 48 is in the position shown in Figure l, and the valve is then manually opened, the contacts will assume the various positions illustrated in Figure l0.

The operation will be described first with particular reference to Figure 12 which shows a conventional 3-wire thermostat vand a system so wired that the valve will close slowly when the space to be heated has reached the desired temperature. Assuming that the valve is closed and that the various parts occupy the relative positions shown in Figure 1, the cams 90 and 92 and the various contacts on the panel 88 assume the positions shown in Figure 7 and diagram.- matically illustrated in Figure 12. Referring more particularly to Figure l2, the bimetallic element |80 of the room thermostat carries a double face contact |82 which is shown positioned midway between the contacts |84 and |86 and the room is therefore at desired temperature under which condition the valve is closed as indicated. When the space |2 becomes cold, the bimetallic element |80 will move contact 82 into engagement with contact |84 to set up the following initial energizing circuit for the motor 42; secondary of transformer |88. wire |90. wire |92, limit control |94 (any desired tvpe of limit control). wire |96, safety pilot |98, wire 200, wire 202. bimetallic element |80. contact 82. contact |84, wire 204, contact |30. contact |28, lever |24. wire 208. motor 42, wire 208. and wire 2|0 hack to secondary of transformer |88. The secondary |88 of the transformer cooperates with a primary 2| 2 which is connected into a live line.

As the motor rotates, upon the setting up of this initial energizing circuit, the cams 90 and 92 will begin to rotate and the cam 50 will also rotate towards its position in which it raises the pivoted electro-magnet 54. After the cams -90 and 92 have rotated a small amount, the cam 90 will depress the arm ||2 and cause maintaining switch contacts ||8 and |20 to engage. This results in the setting up of the following maintaining circuit for the motor to insure that the motor will remain energized for a sumcient length of ltime to move the cams and 92, and consequently the cam 50, through independently of the room thermostat contacts: secondary of transformer |88, wire |90, wire 2|4, contact |20, contact ||8, lever arm I|2, wire 206, motor 42, wire 208, wire 2|0, and back to secondary of transformer |88. Since the room thermostat contacts are not included in this circuit, the motor will rotate the cams 50, 90 and .'32 through 180 once it has started, even though the room thermostat contacts should become separated. In fact the initial energizing circuit is broken shortly after the cams begin to rotate due to separation of contacts |28 and |30 upon displacement of cam 92. The room thermostat contacts thus only carry the load for the motor for a short time during the beginning of the cycle of operation.

An energizing circuit for the coil 58 of electromagnet 54 -is also set up shortly after the cams 90 and 92 begin to rotate and lever arm 98 has been raised so that contacts'|06 and |08 engage. This energizing circuit is as follows: secondary of transformer |88, wire 2|0, wire 2|6, electromagnetic coil 58, wire 2|8, wire 220, contact |08, Contact |06, lever arm 98, Wire 222, wire 200, safety pilot |98. wire |96, limit control |94, wire |92, and wire |90, back to secondary of transformer |88. As before stated, the motor continues to operate until the cams 50, 90 and 92 operate 180 from the position shown in Figure I2. During the course of this operation the cam 50 raises the electro-magnet 54 and the armature 64 will follow the same because of the fact that the coil 58 is energized. Therefore, the valve will be moved into open position by means of the cam or eccentric 50. Just as the cams reach their position in which cam 50 has fully raised the electro-magnet 54 and consequently fully opened the valve which is being controlled, the lever ||2 rides ofi the concentric edge 94 of cam 90, and drops into one of the notches or recesses thereby allowing contacts I8 and |20 to separate and break the secondary energizing circuit of the motor 42. At this stage the circuit which initially energized motor 42 has already been broken due to separation of contacts |28 and |30 as previously explained. The contacts assume the relative positions shown in Figure 8, wherein the contacts |06 and |08 are held in engagement by cam 92. Coil 58 therefore remains energized.

Closing of the contacts |82 and |84 when the parts are in the positions shown in Figure 12 thus results in the setting up of a' condition wherein theelectro-magnet 54 is raised and energized, the armature 64 is held adjacent thereto, the valve is open and the motor 42 is deenergized. The valve cannot run the motor and gear train backwards and return to closed posi- .tion under the influence of spring 30 because the cam 50 is on dead center with respect to the lever 82.

If it be assumed that the valve is open and the parts are in the positions described above, and that the room heats until contacts |82 and |84 separate, there will be no action in the system. When the room heats to such a degree that the thermostat will move contacts |82 and |85 into engagement, however, the following initial energizing circuit for motor 42 will be set up: secondary of transformer |88, wire |90, wire |92, limit control |94, Wire |96, safety pilot |98, wire 200,

wire 202, bimetallic element |80, contact |82. contact |88. wire 224, wire 228. contact |32l contact |28, lever arm |24. wire 208, motor 42, wire 208, and wire 2|0 to secondary of transformer |88.

After the kcams 80 and 82 have rotated a small amount from the positions shown in Figure 8. the lever ||2 rides up on a concentric edge 84 of' cam 80 and moves contacts ||8 and |20 into ensagement to set up the following motor energizing circuit which is independent of the room thermostat |80: secondary of transformer |88, wire 2|0, wire 208, motor 42, wire 208, lever arm ||2. contact ||8l contact |20. wire 2|4 and wire |80 back to secondary |88. As the motor rotates it will operate to slowly rotate cam 50 to the position shown in Figure 12 and will therefore slowly allow the electro-magnet 54 to descend from raised position to the position shown in Figure 12. Since-the contacts |08 and |08 are held in engagement by a concentric surface 84 of cam 80 during return of the parts to the position shown in Figure 12, the coil 58 will remain'energized through its previously described circuit during this period with the result that armature 84 will be held adjacent the electro-magnet 54 during the entire time and the valve will be closed very slowly. As the parts return to the positions shown inFigure 12 the energizing circuit of coil 58 will be broken because of separation of contacts |08 and |08 when arm 88 drops into a notch of cam member 80 as shown in Figure 12. The Y energizing circuit for motor 42 will also be broken because lever |2 will drop into the opposite notch and allow contacts ||8 and |20 to separate, and

the valve will be completely closed. At the same time the cam 92 has depressed lever arm |24 so that contacts |28 and |30 are in engagement and the circuit for initially energizing the motor upon re-engagement of contacts |82 and |84 due to temperature drop, is prepared. The parts will be positioned asfshown in Figure 12 and the system ready for a new cycle of operation.

If it now be assumed that a power failure occurs while the parts are in the position illustrated in Figure 12, there will be no action in the system. The valve will of course remain closed as long as the power failure persists even though the room thermostat is calling for heat. On the other hand, if a power failure occurs while the cam 50 is holding electro-magnet 54 in raised position and the valve is open, the coil 58 will become de-energized and the armature 84 will drop thus allowing the valve to be closed instantly under the action of spring 30. As the valve closes under this spring action the lever |48 is allowed to drop so that the contacts |52 and |54 may engage as shown in Figure 12. In other respects the contacts are positioned as shown in Figure 8. Upon resumption of power the motor is energized through the following circuit which is independent ofV the room thermostat and other controls: secondary of transformer |88, wire 2|0, wire 208, motor 42, wire 208, lever arm |24, contact |28, contact |32 (these contacts are of course closed under these conditions), wire 228, wire 228, lever arm |50, contact |52, contact |54, wire 2|4, and wire |80 to secondary of transformer |88.

When the cams have rotated a slight amount, contacts ||8 and |20 will close to set up the following circuit which is independent of contacts |28 and |32 which contacts will be separated later by cam 82: secondary of transformer |88, wire |80, wire 2|4, contact |20, contact H8, lever arm II2, wire 208, motor 42, wire 208, and wire 2|0 back to secondary |88. The motor will remain energized by means of this circuit until the cams 50, and 82 together with the other parts are brought back into the positions shown in Figure 12 whereupon the room thermostat automatically takes over control of the valve. That is to say. if the room thermostat is calling for heat at this t.me, the necessary motor energizing circuit through contacts |82 and |84 is completed and the valve is opened, but if the room is at the desired temperature the parts merely remain as they are. This is also true it the contacts |88 and |82 are in engagement.

If it now be assumed that power failure occurs while the parts are in the position shown in Figure l2 and that the operator then partially opens the valve manually by means of the handle |38. the cam |58 will rotate lever arm |58 in counterclockwise direction so that contacts |82 and |88 will engage. Upon engagement of these contacts followed by continued rotation of lever |58 in counter-clockwise direction, the lever ||2 will be rotated in clockwise direction and will move away from the notch or recess in cam 80 and cause contacts |8 and J|20 to engage. At the same time lever arm |50`will be rotated in clockwise direction, due to engagement between pin 10 and lever |48, and contacts |52 and |54 will be separated. The position of the contacts under these conditions is illustrated in Figure l0. The valve is thus partially open and when power is resumed the following motor energizing circuit is set up for the purpose of again automatically placing the 'entire system under the control of the room thermostat: secondary of transformer |88, wire 2|0, wire 208. motor 42, wire 208, lever varm ||2, contact ||8, contact |20. wire 2|4 and wire |80 back to transformer |88.

When the valve is raised upon rotation of handle |38 and consequent engagement of pin 10 and arm |38 as before described, an upward force is exerted against the link 88 whereby the armature 841s securely pushed into engagement with the electro-magnet 5 4 which is partially raised as a result. Thus, upon resumption of power after the valve has been manually opened under these circumstances, the armature 84 will be in physical engagement with the core of electro-magnet 54 whose coil 88 is energized by means of the following circuit: secondary o! transformer |88. wire 2|0, wire 2|8, energizing coil 58, wire 2| 8, wire 230, lever arm |58. contact |82, contact |88, arm |10. arm ||2, contact ||8. contact |20, wire 2 4, and wire |80 back to transformer |88.

Thus, when power is again continued, the motor will operate to move electro-magnet 54 into the raised position shown in Figure 2 and -since the coil 58 is energized, the armature 84 will be retained in engagement with the electro-magnet and the valve will be fully opened. During the raising of the valve, the pin 10 will be raised out of engagement with the notch |42 on the end of lever, |38 with the result that lever |38 will be released and will rotate into the position shown in Figure 12, together with cam |58. 'Ihls resultsvin separation of contacts 82 and |88 although contacts' I8 and |20 will remain in engagement because of the fact that arm ||2Tis riding on one of the concentric edges 84 of the cam 80 and the motor circuit will not be broken. The coil 58 will remain energizedin spite of the separation of the contacts |82-|88 through the following circuit which includes contacts |08 and |08. closed by the cam 80: secondary of transformer |88, wire 2| 0, wire 2|8, magnet coil 58, wire 2|8, wire 220, contact |08, contact |08, lever arm 98, wire 222, wire 200, safety pilot |98, wire |98, limit control |94, wire |82, and wire |90 back to secondary |88.

When the valve is thus fully opened, the cams 90-92 will be rotated 180 from the position shown in Figure 12 and the relay coil 58 will remain energized through the circuit just described since contacts |08 and I 08 are held closed by cam 92. However, the arm ||2 is dropped into one of the notches of cam 90 therebyto cause separation of contacts ||8 and |20 and the motor will be de-energized unless the room happens to bel so hot that contacts |82 and |88 are in engagement. When the valve reaches fully open position, the system is therefore again under complete control of the room thermostat and the means for manually raising the valveare automatically returned to inoperative position. The contacts are as shown in Figure 8.

If it now be assumed that power failure occurs while the valve is being held open as illustrated in Figure 2, the cams 50, 90 and`92 will be 180 from their positions shown in Figure 12'l the electro-magnet 54 will be raised, and armature 84 will be dropped to allow the valve to move into closed position under the action of spring 30. If the valve is then partially opened by means of the manually operated handle |38, the armature 64 will remain separated from the core of electromagnet 54 and the various contacts on the panel board will assume the positions illustrated in Figure 9.

When power is resumed the motor will be energized by means of the following circuit; vsecondary of transformer |88, wire 2|0, wire 208, motor 42, wire 208, lever ||2, contact H8, contact |20, wire 2|4, and wire |90, back to transformer |88. The contacts ||8 and |20, which control this motor circuit, will remain continuously in engagement as long as the lever |38 remains in position" to, mechanically hold the valve open, and the lever |38 will remain in such position until the motor has rotated cam 50 through nearly 360. This is true because of the fact that the armature 84 was separated from the electro-magnet upon resumption of power and the magnet cannot operate to fully raise the valve and release lever 38 until cam 50 returns to the position shown in Figure 12, thereby to cause armature 84 to be mechanically placed in engagement with electro-magnet 54, and has then rotated nearly 180 additionally in order to raise electro-magnet 54 together with armature 84 and the valve stem with the result that pin is raised above notch |42 on the end of lever |38 thereby to release the latter. The release of lever |38 will not cause separation of contacts ||8 and |20. These will remain in engagement until the cam 50 has completed the full revolution of 360 and fully raised the valve because of the fact that arm ||2 rides on one of the con-l centric surfaces 94 of the cam 90 at the instant when lever |38 is released. After the completion of the 360 or revolution, it will be obvious that the system is again under the complete control of the room thermostat.

Thus, when the system is wired as shown in Figure 12, the valve is always returned from open V to be noted that although means for manually opening the valve upon power failure areprovided, the control of the valve is automatically taken over by the room thermostat upon resumption of power, irrespective of the positions of parts when power failure occurred. The system provides complete safety as against power failure, enables manual control of the valve during power failure, and insures resumption of complete automatic control upon recurrence of power even though the valve has been manually opened.

The system illustrated in Fig. 13 results ln a quick closing 'of the valve whenever the room thermostat indicates that desired room temperature has been reached. The operation of the system when wired as shown in Figure 13 will now be described, reference being had particularly to this figure wherein reference numerals like those in Figure 12 have been used wherever possible.

When the room is at desired temperature, the valve is closed and the contacts |82 and |84 are open, the various parts being in the relative positions shown in Figure 13 under normal conditions of operation. If the room now becomes cold, the contacts |82 and |84 move into engagement to set up the following circuit for initially energizing the motor 42: secondary of transformer |88, wire |90, wire |92, limit control |94, wire |98, safety pilot |98, wire 202, room thermostat |80, contact |82, contact |84, Wire 204, contact |30, contact |28, lever |24, wire 208, motor 42, wire 208, and wire 2|0, back to secondary After the motor has operated for a short time, the lever arm ||2 will ride on one of the concentric edges 94 of cam 90 and maintaining switch contacts ||8 and |20 will be closed in order to set up the following motor energizing circuit which is independent of the room thermostat and thereby insures the completion of a half revolution on the part of the cams -92,` and cam 50, independently of the room thermostatz' transformer |88, wire |90, wire 2|4, contact |20, contact ||8, lever ||2, wire 208, motor 42, wire 20B, wire 2|0, and secondary of transformer |88.

When the cam 90 has rotated sufficiently to lift lever 98 and move contacts |06 and |08 into engagement, the following circuit for energizing the magnet coil 58 is s'et up so that armature 84 will be held in engagement with the core of electro-magnet 54 and the valve will be opened upon a raising of the electro-magnet by means of the cam 50: secondary of transformer |88, wire |90, wire |92; limit control |94, wire |96, safety pilot, |98, Wire 202, thermostat |80, contact |82, contact |84, wire 204, wire 232, lever arm 98, contact |08, contact |08, wire 220, wire 2|8, energizing coil 58, wire 2|8 and Wire 2|0 back to secondary of transformer |88. It will be noted that the limit control and the safety pilot as well as the thermostat are in-the relay energizing circuit. Any of these may therefore operate to de-energize the relay and close the valve in the same manner as upon the occurrence of power failure.

After the cams 50, 90 and 92 are rotated through by the motor 42, the cam or eccentric 50 has fully raised the electro-magnet 54 together with its armature 84 with the result that the valve has been fully opened against the action of .its spring 30 which urges it into'closed position. At this stage of operation the lever I2 drops into one of the notches or recesses formed in cam member 90 thereby to break the motor energizing circuit and it will be noted that the initial energizing circuit of the motor was previously broken upon separation of contacts |28 and |30 due to rotation of cam 92 away from the position shown in Figure 13. The contacts |06 and |08 will not be separated at this 180 position, or open position, but will be held in engagement by the cam 92.

When the valve is open, therefore, the motor is deenergized, coil 58 is energized, the room thermostat contacts |82 and |84 are in engagement, the remaining contacts are in the positions indicated in Figure 8, and the cam 50 and electro-magnet 54 assume the full line positions shown in Figure 2. The valve is unable to reverse the motor and close under the action of spring 30 because of the position of thecam 50 which is on dead center with respect to the roller 16 on the arm 82 of the electro-magnet,

If it now be assumed that the room has become heated to the desired temperature due to opening of the valve, contacts |82 and |84 will separate thereby breaking the energizing circuit for coil 58 with the result that the armature 64 will drop down into the dotted line position shown in Figure 2 and allow the valve to be closed under the action of spring 30. Thus, the closing of the valve will occur very quickly and abruptly. When the valve was in raised position the pin 10 engaged the lever |46 and thereby held contacts |54 and |52 out of engagement as illustrated in Figure 8 but upon closure of the valve the pin 10 drops away from lever |48 and the arm |50 rotates under the influence of its spring to move contact |52 into engagement with contact |54 and set up the followingY circuit for initially energizing the motor for the purpose of returning the cams to their positions shown in Figure 13; secondary of transformer |88, Wire 2|0, wire 208, motor 42, wire 206, lever |24, contact |28, contact |32 (these contacts are closed under these conditions), wire 228, lever arm |50, contact |52, contact |54, wire 2|4 and wire |90 back to secondary of transformer |88. After the cams have rotated a small amount, the cam 80 depresses lever ||2 so that contacts ||8 and |20 move into engagement. Later the cam 92 depresses lever arm |24 thereby separating contacts |28 and |32 and breaking the circuit for initially energizing the motor just described. However, the motor will remain energized until the parts are back in 'the position shown in Figure 13 by means of the following circuit which includes the contacts ||8 and |20: transformer |88, wire 2|0, wire 208, motor 42, wire 206, lever arm ||2, contact ||8, contact |20, wire 2|4, Wire |90, and secondary of transformer |88. Upon completion of the half revolution of cams 90 and 92 the lever arm ||2 drops back into the notch in cam 90 as shown whereupon contacts ||8 and are separated and the motor 42 is deenergized. All of the parts are then in the position shown in Figure 13 and the system is ready for the next cycle of operation. Thus, in normal operation the room will become cold as a result of the closing of the valve, contacts |82 and |84 of the room thermostat will engage, and the valve will again be opened as described above.

Upon the occurrence of power failure while the electromagnet 54 is in raised position and the valve is open, the armature 84 simply drops and allows the valve to close under the action of spring 30 in the same manner as this occurs upon the opening oi' contacts 82 and |84 of the room 75 thermostat in normal operation. Upon resumption or power, the motor rotates the cams through 180 to return the parts to their positions shown in Figure 13, as already described. and place the system under complete control of the thermostat. Thus, if contacts |82 and |84 are separated the parts remain as in Figure 13, but if the room is cold the valve is automatically opened by the motor as in normal operation.

If it now be assumed that power failure occurs while the parts are in the positions shown in Figure 13 and that the valve is then partially opened by means of the manually operated lever |36, the various contacts on the panel board will assume the positions illustrated in Figure 10 and the armature 64 will be in engagement with the core of electro-magnet 54 as explained in connection with the operation of the system shown in Figure 12. Upon resumptionof current while the parts are so arranged, the motor 42 will be initially energized by means of the following circuit: secondary of transformer |88, wire 2|8. wire 208, motor 42, coil 206, lever arm ||2, contact 8, contact |20, wire 2|4, and wire |90 back to secondary of transformer |88. After the motor has moved the cams an amount suilicient to rotate electro-magnet 54 to the extent that pin 10 will be moved out of engagement with lever |38, the magnet coil being energized by a circuit to be described later, the lever |38 will be released, and contacts |62 and |68 will be separated. However, the contacts ||8 and |20 will be held in engagement by means of the'cam 8l and the motor `will continue to be energized by the initial energizing circuit above described so that the cams 50, and 92 will at least be rotated through into open position.

As soon as the motor is energized as just described, the coil 58 of electro-magnet 54 becomes energized by means of the following circuit which is independent of the room thermostat but is dependent upon the manually closed contacts |62 and |68: secondary of transformer |88, wire 2|0, wire 2|6, energizing coil 58, wire 2|8, wire 230, lever arm |58, contact |62, contact |68, arm |10, lever arm ||2, contact ||8, contact |28, wire 2|4, and wire |80 back to secondary or transformer |88. Due to the energization of coil 58 the armature 64 will remain in engagement with the core ofthe electro-magnet and the valve will be raised upon rotation of cam 50. When the magnet rotates sufficiently to lift pin 10 out of engagement with the manually oper. ated lever |38, this lever and its co-operating cam |56 drop back into the positions Figure 13 and the contacts |62 and |68 sepa rate, thereby breaking the energizing circuit i'or the magnet coil 58 which has just been described.

Assuming that the contacts |82 and: |84 of the room thermostat are open at this instant, the coil 58 will become de-energized, armature 84 will drop away from the electro-magnet 54, and the valve will quickly close under the action of spring 30, but the opening of contacts4 62 and |68 will not interfere with the motor energizing circuit. On` the contrary the-motor will continue to be energized until all of the parts are back in the positions shown in Figure 13. The motor energizing circuits for the first half oi' the revolution of the cams have just been described and the energizing circuits for the last half of the revolution are the same as those described in connection with normal operation upon separationof contacts |82 and |84 when the room reaches desired temperature. Thus, in the event shown lnthe room thermostat is not calling for heat, the valve will automatically be closed and all of the parts will assume the positions shown in Figure 13 wherein the room thermostat is in full control, upon resumption of power.

If it be assumed, however, that the room ther mostat was calling for heat at the instant when the pin 10 released the lever |88, the electromagnet 58 would not become de-energized due to the separation of contacts |62 and |68 but would remain energized through the following circuit which includes the contacts |82 and |84 of the room thermostat: secondary of transformer |88, wire 2|0, wire 2|8, magnet coil 58, wire 2|8, wire 220, contact |08, contact |06, lever arm 88, wire 232, wire 204, contact |84, contact |82, thermostat |80, wire 202, safety pilot |98, wire |96, limit control |94, wire |82 and wire |00 back to transformer |88. Due to the continued energizatlon ot coil 58, armature 64 will remain attracted by the electro-magnet 54 and the valve will move into fully open position. When the valve is thus fully opened, the parts will be positioned just as they are when the thermostat is calling for heat and the valve is fully opened under normal conditions of operation. The manually controlled lever |38 will be moved back into the position shown in Figure 13 under the action of its spring and the system will be under complete and normal control of the room thermostat. It will be noted that the circuit for energizing the coil 58 until such time as pin 10 is raised a suiicient amount to release lever |38 is completed irrespective of the condition of the room thermostat. Thus, the means for manually setting the valve open are always released upon the resumption of power, and full control is immediately assumed by the thermostat.

If it be assumed that power failure occurs while the thermostat is calling for heat and the valve is being held open by the electro-magnet 54, and that the operator thereafter manually rotates lever |38 to partially open the valve, the position of the contacts will be those illustrated in Figure 9 and the armature 64 will be separated from the electro-magnet 54. Upon the resumption of power the motor will be energized through the following circuit: secondary of transformer |88, wire 2|0, wire 208, motor 42, wire 206, lever arm ||2, contact ||8, contact |20, wire 2|4, and wire |80 back to secondary of transformer |88. This circuit will cause rotation. of vthe motor until the cams rotate 180 to reach the positions shown in Figure 13 at which time the armature 64 will be mechanically moved intoengagement with the core of electro-magnet 54. That is to say, the cams and electro-magnet will occupy the dotted line positions shown in Figure 5 and the contacts will assume the positions shown in Figure wherein the contacts |I8 and |20 are in engagement even though a notch on cam member 90 is opposite the arm ||2. The motor will therefore continue to be energized by means of the circuit just described above thereby to rotate the cams another 130" into the position which they occupy when the valve is opened under normal conditions of operation and without the aid of the manually controlled lever |38. During the course of this rotation, the energizing coil 58 will continue to be energized, the armature 84 will remain attracted by the electro-magnet 54, and

.the valve will be raised toward fully open position. When the pin 10 rises clear of the notch in the end of lever |38, this lever will move into the position shown in Figure 13, together with its co-operating cam |56, and cause separation o! contacts |62 and |68. However, contacts ||8 and |20 will not separate and cause deenergiza.- tion of the motor inasmuch as the lever arm I|2 will be riding on one of the concentric edge surfaces of the cam member 90. The motor operates until the valve is full open whereupon the entire system is again under the control of the room thermostat. I

Since the thermostat was calling for heat in the operation just described. the coil 58 remained energized when the valve reached open position and the motor 42 became deenergized. On the other hand, if the contacts of the thermostat had been disengaged, the coil 58 would have become de-energized, and the various parts would have returned to the positions indicated in Figure 13 as in normal operation.

While quick closing of the valve has been described in connection with a simple two-Wire thermostat it will be obvious that quick closing can, if desired. also be obtained with a thermostat providing for a temperature differential between opening and closing of the valve.

A thermostat having two contacts which are sequentially closed on a temperature drop as shown in Figure 15 may be substituted for the thermostat in Figure 13. As far as possible corresponding parts of Figure 15 carry the same numbers as in Figure 13. On a, temperature drop contact 256 engages contact 258 but this of itself does not energize the relay for the circuit is broken by contacts |06 and |08. On a still further temperature drop contact |82 engages contact |84 which operates the motor for a half cycle as explained in connection with Figure 13. The relay is now energized through a circuit including contacts 256 and 258 and will therefore hold the valve open until these contacts are separated by a, temperature rise.

In the case of both the two-wire thermostat shown in Figure 13 and the three-wire thermostat shown in Figure 12, the operation of any of the limit controls or safety pilot affects the instrument in exactly the same way as power failure since it causes de-energization of the relay and the motor will not subsequently operate to open the valve until the limit control is again placed back to normal.

Whenever the electro-magnet 54 is rotated about its pivot 56, it will be apparent from Figures 1 and 2 that the lever 80 will be rocked and that the shaft 82 which is secured thereto will also be correspondingly rocked. The secondary air draft damper I0, Which is shown in Figure 11, is opened and closed by means of a lever 240 which is secured to the shaft 82. Thus, the damper I0 is moved into open position whenever the valve is open and is moved into closed position whenever the valve is closed. As a result of this no secondary air draft may circulate through the combustion chamber when combustion is not taking place and all of theheat within the cornbustion chamber is conserved.

As shown in Figure 6, a mercury switch 250 is mounted in -a holder fixed on the side of the electro-magnet 54. When the electro-magnet is in the position shown in Figure 1 the circuit across the contacts of the mercury switch is open and when the electro-magnet is in the position shown in Figure 2, the position of the mercury switch is such that the circuit across the electrodes is closed. 'I'he mercury switch controls the energizing circuit of the motor 252 of a warm air circulating fan 8 which is energized through a circuit which includes the power supply III and the mercury switch Ill connected by suitable circuit conductors. lThus, when the valve is closed the mercury switch III holds the energizing circuit o1' the warm air circulating fan motor open but when the valve is held open by means of electromagnet ll, the mercury switch closes a gap in the-circuit for the fan motor. Thus, the fan will not operate to circulate hot air except when combustion is taking place. It will of course be understood that any other of the conventional limit controls may be included in the circuit of the warm air circulating tan motor.

In commercial practice, the instrument comprising the motorized valve above described is internally wired as illustrated in Figure 7. By properly selecting the external connections a system like that shown in Figure l2. Figure 13 and Figure 15 may be selectively set up as follows:

If the instrument is to form part of a system as shown in Figure 12, binding post 300 is connected to thermostat contact |00, and post 302 is connected to thermostat contact |01. Post 304 is connected to the bimetal and the safety pilot and limit control are connected in series across posts IM and 3|0. The transformer secondary |08 is connected across posts 3| 0 and SI2.

It the instrument is used in a system such as shown in Figure 13, posts 302 and 304 are both connected to xed thermostatic contact |04. The post 306 is connected to bimetal |00. The limit control and safety pilot are connected in series between posts 300 and M0. The transformer secondary |08 is connected across posts 3|0 and 3| 2.

If the instrument is used in a system such as shown in Figure 15, post 302 is connected to the fixed thermostat contact III, and post 804 is connected to the fixed thermostatic contact 250, post 306 is connected to the bimetallic blade |00. I'he limit control and safety pilot are connected in series between posts 306 and 3I0. The transformer secondary |80 is connected across posts lll! and SI2.

In the following claims, reference to valves will be understood to cover any desired types of heat control members such as dempers and the like. Also, references in the claims to closed position of the valve will be understood to include also any desired predetermined position of the valve in which it causes the heater to supply a minimum supply of heat.

I claim as my invention:

1. In combination, a heater, a member controlling the heat supplied thereby, an electric motor, means responsive to a heater condition for controlling said electric motor, means including an electro-magnet connecting said motor and said heat control member to move the latter between a position in which it supplies a lesser amount of heat and a position in which it supplies a greater amount of heat, means associated with said positioning means for returning said heat control member to its position in which it causes the heater to supply a lesser amount of heat, upon the occurrence of power failure while said member is in position to supply a greater amount of heat, and manually operable means for setting said heat control member in a position in which it supplies a greater amount of heat while such power failure obtains.

2. In combination, a heater. a valve controlling the heat supply and biased to move to closed position, a thermostat, and means controlled by the thermostat and including an electric motor and an electro-magnet the energisation or which is controlled by the thermostat for positioning the valve, said means being operative to position the valve only when the electro-magnet is energized and being inoperative to hold the valve open when the electro-magnet is de-energized, whereby the valve is automatically returned to closed position whenever the electromagnet becomes de-energized while the valve is open.

3. In combination, a heater, a valve controlling the operation of the heater and biased to move to closed position, a thermostat, and means controlled by thethermostatand including an electric motor and an electro-magnet the energization of which is controlled by the thermostat adapted to be connected to a common current source ior positioning the valve, said means being operative to move the valve away from closed position only when the electro-magnet is energized and being inoperative to hold the valve open when the electro-magnet is deenergized, whereby the valve is automatically returned to closed position upon the occurrence of power failure while the valve is open.

4. In combination, a heater, a member controlling the heat supplied thereby, a thermostat in the space heated by said heater, a motor controlled by the thermostatan electro-magnet positioned by said motor, an armature adapted to be engaged with the electro-magnet by the motor and to be heid by said electro-magnet when the latter is energized, and means connecting said armature and heat control member for positioning the latter.

5. In combination, a valve, means biasing said valve to closed position, a control switch com.- prlsing a pair of contacts adapted to be closed, an electric motor controlled by the switch, an electro-magnet, circuit conductors adapted to interconnect said switch contacts, motor and electromagnet to a common source of electrical energy, means associated with said motor and electro-magnet for moving the valve from closed to open position when the switch contacts are closed, means for disconnecting said motor Iromthe energy source when it has moved the valve to open position, means associated with said electro-magnet for holding the valve in open position while the motor is deenergized, means for again energizing the motor when the switch contacts are open, means associated with said motor and electro-magnet for slowly returning the valve from open to closed position, said electro-magnet being operative to release the valve for movement into closed position under the influence oi.' the biasing means and independently of the motor upon the occurrence of power failure, means for manually setting said valve in an open position against its bias during such power failure, and means for rendering said manual means inoperative and automatically returning the valve to the control of the switch upon the resumption of power.

6. In combination, a valve, means biasing the valve to closed position, a control switch comprising a pair of contacts adapted to be closed, an electric motor, an electro-magnet adapted to operatively connect said motor and valve when energized and disconnect the .same when deenergized, circuit conductors adapted to interconnect said switch contacts, motor and electromagnet to a common source of electrical energy, means associated with said motor and electromagnet for moving said valve from closed to open position and maintaining the same in such position when the switch contacts are closed, means for disconnecting said electro-magnet from the source of electrical energy when the switch contacts are opened thereby to release said valve from the motor for quick closure under the influence of said biasing means, and means for again energizing the motor when the valve is thus closed.

7. In combination, a valve, means biasing the valve to closed position, a control switch com-- prising a pair of contacts adapted to be closed, an electric motor, an electro-magnet adapted to operatively connect the valve and motor when energized and to operatively disconnect the same so that the valve may move independently of the motor when deenergized, circuit conductors adapted to interconnect said switch contacts, motor and electro-magnet to a common source of electrical energy, means associated with said motor and electro-magnet for moving the valve from closed to open position upon closure of the switch contacts and for maintaining the same in such position until the switch contacts are opened, means for disconnecting said motor from the energy source when the valve reaches open position, said valve being adapted to move from open to closed position independently oi' the motor upon the occurrence of a power failure with consequent de-energization of said electromagnet, means for manually setting said valve in open position after such power failure, and means for rendering said manual means inoperative and automatically returning said valve to the control of the switch upon the resumption of power.

8. In combination, a heater, a valve for controlling the heat supply and biased to closed position, a thermostat adapted to close a pair of contacts when the temperature of the medium adjacent the thermostat falls below a desired value, an electric motor, an electro-magnet adapted to operatively connect the valve and motor when energized and to operatively disconnect the same so -that the valve may move independently of -the motor when de-energized, circuit conductors adapted to interconnect said thermostat contacts, motor and electro-magnet to a common source of electrical energy, means associated with said motor and magnet for moving said valve from closed to open position upon closure of the thermostat contacts and for maintaining mon source of electrical energy in a manner whereby the energization of the motor and electro-magnet are under the control of the thermostat, means associated with said motor and magnet for moving the valve from closed to open position and maintaining the same in such position during engagement of the thermostat contacts, means for disconnecting said motor from the energy source after the valve reaches open posi the same in such position while these contacts l are closed and the current source is operative, means for disconnecting said motor from the energy source when the valve reaches open -position, means for manually setting the valve in open position after the occurrence of a power failure while the space being heated is at desired temperature and the valve is closed, and means for automatically rendering said manual means inoperative and returning the valve to the control of the thermostat upon the resumption of power.

9. In combination, a heater, a valve for controlling the heat supply and biased to closed position, a thermostat adapted to close a pair of tion, and means for automatically restoring the valve to the control of the ,thermostat upon the resumption of power after the valve has dropped from open to closed position upon the occurrence of a power failure and consequent de-energization of the electro-magnet.

10. In combination, a valve casing, a valve movable therein between an open and a closed position to regulate the passage of fluid therethrough, means for biasing the valve to closed position, an electric motor mounted upon the valve casing, an electro-magnet pivoted with respect to the valve casing, means connecting the motor and magnet for imparting pivotal movement to the latter upon actuation of the former, an armature associated with said magnet and movable relative thereto when de-energized but held by the magnet when energized, and means connecting the armature and valve for positioning the latter, said armature being released by the electro-magnet and the valve being free to move the closed. position under the iniluence of its` biasing means upon the occurrence of power i'ailure and consequent de-energization of the magnet.

1l. In combination, a valve casing, a valve movable therein between an open and a. closed position to regulate the passage of nuid therethrough, a. spring for biasing the valve to closed position, an electric motor mounted on the valve casing, an electro-magnet pivoted with respect to the valve casing, an armature for the magnet, saidmagnet being of sullcient strength to forcibly retain the armature adjacent thereto but of insufficient strength to attract the armature to itself when appreciably spaced therefrom, means connecting the motor and electro-magnet for raising and lowering the latter upon rotation of the former, and means connecting the armature and valve for raising the valve upon a raising of the electro-magnet, said last named means further being operative to mechanically move the armature into engagement with the electro-magnet upon a lowering of the electro-magnet by the motor.

12. In combination, a heater, a heat control member for controlling the heat supply, means biasing the heat control member to heat diminishing position, a device responsive to a condition produced by the heater and adapted to open and close a pair of contacts, a motor under the control of said condition responsive device, electrically operated means adapted to operatively connect said motor and heat control member when energized and disconnect the same when deenergized, circuit conductors adapted to interconnect said device contacts and electrically operated means to a common source of electrical energy, means associated with said motor and electrically operated means for moving said heat control member from heat diminishing position to heat increasing position and maintaining the same in such position when the device contacts are closed, means for disconnecting said electrically operated means from the source of electrical energy when the device contacts are opened in response to the heater condition thereby to release said heat control member from the motor for quick movement to heat diminishing position under the influence of said biasing means.

13. A heat control system including in combination, a member to be controlled and which is biased to a rst position, a control member, switching means movable to closed position upon movement of the control member, electric motor means, an electro-magnet adapted to operatlvely connect saidmotor means and controlled member when energized and disconnect the same when de-energized, circuit conductors interconnecting the switching means, motor means and electro-magnet to a common source of electrical energy in a manner whereby the motor means and electro-magnet are under the control of the switching means, means associated with said motor means and electro-magnet for initiating movement of said controlled member toward a second position when said switching means is moved to closed position by said control member, maintaining switching means operated to closed position upon initial movement of said motor means whereby said motor means is maintained energized independently of said rst mentioned switching means, and means for operatively deenergizing said motor means when the controlled member has been moved to its second position,

said electro-magnet being operatlveto release the controlled member for movement to its ilrst position under its bias and independently of the motor means upon the occurrence of a power failure.

14. In combination. a heater, a heat control member movable between open and closed positions and biased to closed position, a thermostat adapted to close a rst pair of contacts when cold and a second pair of contacts when hot, therel being an intermediate temperature at which neither pair of contacts is closed, electric motor means controlled by said pairs of contacts, an electro-magnet adapted to operatively connect said motor means and heat control member when energized and disconnectthe same when de-energlzed, circuit conductors inter-connecting the pairs of contacts, motor means and electro-magnet to a common source oi.' electrical power whereby the motor means and electro-magnet are controlled by said pair of contacts, circuits for the motor means controlled by said cold pair of contacts and said hot pair of contacts for causi118 opening and closing of said heat control member, and maintaining switching means operated upon initial movement of said motor means for maintaining the particular motor circuit independently of the cold or hot pair of contacts as the case may be, said electro-magnet being operative to.release said heat control member for movement to closed position independently of the motor means upon the occurrence of a power failure.

l5. A valve for controlling the flow of fuel to a gas iired furnace, electro-responsive means for operating said valve, a circuit including a source of current supply and a. thermostatic switch connected to control the operation of said electroresponsive means, manually operable means arranged to operate said valve when said circuit is deenergized and to be automatically rendered inactive when the circuit is energized, a switch arranged to be operated by said manually operable means and to shunt said thermos-tatie switch when said valve is moved by the manually operable means, and a second switch arranged to be 75 electro-magnet to elect closed by said electro-responsive means when energlzed and to cooperate with said thermostatic switch when the latter is heated above a predetermined temperature to deenergize said electro-responsive means.

18. In combination, a iluid flow controlling member, means biasing the fluid now controlling member into a position wherein a minimum flow of fluid is permitted, a motor, an electro-magnet positioned by the motor, an armature pivotally connected with respect to the electro-magnet and adapted to be held in contact therewith when the latter is energized, and a link pivotally connected to the armature and also connected to the heat control member ior positioning the latter.

17. A iluid flow controlling element, an electrical actuator therefor, an electro-magnet positioned by said actuator, an armature adapted to be engaged with the electro-magnet by the actuator to be held by said electro-magnet when the latter is energized, means connecting said armature and fluid dow controlling element for positioning the latter, and control means for controlling the energization of said actuator and said movement of said fluid ow controlling element between different ilow controlling positions.

18. In combination, a iluid flow controlling element biased to one flow controlling position, a switch movable from a first to a second circuit controlling position, electrical actuating means, an electro-magnetadapted to operatively connect said actuating means and said element when energized and disconnect the same when deenergized, means controlled by said switch for connecting said actuating means and said electromagnet to a common source of electrical energy and operative upon movement of said switch from said first to said second circuit controlling position to cause said actuating means to move said element to a second flow controlling position against its bias and to maintain the same in such position while said switch is in its second circuit controlling position, said means being operative upon return of said switch to said ilrst circuitcontrollingposition to disconnect said electro-magnet from the source of electrical energy thereby to release the fluid flow controlling element from the actuating means for quick return to the ilrst mentioned position by its bias, and means for again energizing said actuating means when the element reaches said llrst mentioned posltion to return said actuating means to substantially its original position.

19. In combination, a fluid dow controlling element biased to one position, an electrical actuator for the same, means operatively connecting said actuator and said fluid flow controlling element comprising two elements movable away from each other and an electrically operated holding means for holding said elements together, switching means including a control switch operative upon movement of said switch in one direction to cause energization of both said actuator and of said holding means to cause saidactuator to move said element to a second iiow controlling position, said switching means being operative upon said control switch being moved in the opposite direction to effect return of said element to said nrst position and to deenergize said holding means before said switching means terminates its operation.

20. In combination, a valve, an electric motor for actuating the same, means comprising an electro-magnet adapted to operatively connect the valveand motor when energized and to operatively disconnect the same so that the valve may move independently of the motor when deenergized,' switching means including a main control switch operative upon movementof said switch to one circuit controlling position to cause energization of both said motor and said electromagnet to cause said motor to open said valve and to deenergize said motor upon said valve reaching open position, said switching means being operative upon said control switch being moved to a diiferent circuit controlling position to cause return of said valve to closed position and to deenergize said electro-magnet before said switching means terminates its operation.

21. A valve of the character described, comprising a casing having a passageway therethrough, a valve member in said casing and controlling ow through said passageway, automatic means operable to move said valve member toward open position, a thrust member operable to move said valve member toward open position, a rotatable shaft, normally inactive cam means carried by said shaft and operable on said thrust member upon rotation of said shaft, and a spring having one end ilxed and having its other end acting on said shaft, said thrust member having means cooperating with said cam means to hold said shaft against rotation by said spring upon opening movement of said valve member by said cam means, said spring acting to move said cam means to inactive position upon movement of said valve member by said automatic means.

22. A valve of the character described, comprising a casing having a passageway therethrough, a valve member in said casing and controlling iiow through said passageway, a stem on said valve member, electrically energized means cooperable with said stem to move said valve member toward open position, a thrust member operable to move said valve member toward open position, a. rotatable shaft, normally inactive cam means carried by said shaft and operable on said thrust member upon rotation of said shaft, and a helical spring having one end fixed and having its other end acting on said shaft, said spring surrounding said shaft, said thrust member having means cooperating with said cam means to hold said shaft against rotation by said spring upon movement of said valve member by said cam means, said spring acting to move said cam means to inactive position upon movement of said valve member by said electrically energized means. Y

23. In combination, a temperature changing means, a regulator for said temperature changing means biased to a predetermined position in which said temperature changing means is least active, a thermostat, and means controlled by the thermostat for positioning the regulator and including an electric motor and electromagnetically controlled means. the energization of which is controlled by the thermostat, said positioning means being operative to position the valve only when the electromagnetically controlled means is energized and being inoperative to hold the regulator away from said predetermined position when the electromagnetically controlled means is deenergized, whereby the regulator is' regulator is in other than said predetermined position.

24. In a temperature control system, a temperature changing means, a regulating device. for said temperature changing means normally tending to assume a. position in which said temperature changing means is least active, electric driving means for said device, electromagnetically controlled means operative when energized to maintain a driving relation between said device and said driving means, said electromagnetically controlled means being releasable upon deenergization thereof to permit of movement of the device independently of the driving means, a thermostat comprising a thermostatic element and first and second switches sequentially closed in the order named upon a temperature change in one direction, an energizing circuit for said electromagnetically controlled means controlled by said nrst switch, and a. regulating circuit for said driving means controlled by said second switch and effective when closed to cause said driving means to move said regulating device in a direction to increase the temperature changing effect of said temperature changing device.

25. In a temperature control system, a temperature changing means, a regulating device for said temperature changing means normally tending to assume a position in which said temperature changing means is least active, thermostatically controlled electric driving means for said device, electromagnetically controlled means normally energized to maintain a driving relation between said device and said driving means but releasable to permit of movement of the device independently of the driving means, and means responsive to the movement of said driving means for controlling the energization of said electromagnetically controlled means.

26. In a temperature control system, a temper- 4ature changing means, a regulating device for said temperature changing means movable in opposite directions between maximum and minimum temperature changing positions to regulate the operation of said temperature lchanging means and normally tending to move to said minimum temperature changing position, an electrically driven operator for moving said device in opposite directions and having a connection therewith adapted when released to permit of independent movement of the device to minimum temperature changing position, thermostatic means in the space Whose temperature is to be controlled, a switch adapted to be closed by said thermostatic means when the temperature is at one predetermined value and controlling said operator to cause movement of said device toward said minimum temperature changing position, a second switch adapted to be closed by said thermostatic means when the temperature is at a different predetermined value and controlling said operator to cause movement of said device toward maximum temperature changing position, and means operative during the movement of said operator caused by the closure of said first mentioned switch to release said connection automatically.

27. In combination, a main burner, a pilot burner, a valve controlling the flow of fuel to said main burner, means biasing said valve to closed position, an armature connected to said valve, an electromagnet adapted to hold said amature and said valve in valve open position against the action oi said biasing means, but incapable oi' moving said armature into engagement therewith when released, means responsive to the temperature oi' the pilot burner for controlling the energization of said electromagnet.

and means for moving said electromagnet into engagement with said armature when the latter has been released and subsequently moving said electromagnet, said armature. and said valve to valve open position. i! said electromagnet is again reenergized.

28. In combination, a heater, a member controlling the heat supplied thereby and biased to one extreme position; a iirst temperature responsive means responsive to one controlling temperature condition, a motor controlled by the thermostat, an electromagnet, means including a second temperature responsive means responsive to a different temperature condition i'orcontrolling the energization of the electromagnet, an armature adapted to be engaged with the electromagnet by the motor and adapted to be held by said electromagnet against the action of the biasing means when the electromagnet is energized. and means connecting said armature and heat control member for positioning the latter.

29. In combination, a main iiuid fuel burner, a pilot burner, a member controlling the ow of fuel to said main burner, means biasing said member to a iirst position in which ilow oi' fuel to the main burner is prevented, means for holding said member in a second position in which iiow of fuel to the burner is permitted, said holding means including an amature and an electromagnet one of which is connected to said member, means including a device responsive to the temperature of the pilot burner operative when the pilot burner is ignited to energize the electromagnet suiliciently to hold said electromagnet and armature together but insuiiiciently to move them together. and means for moving said electromagnet and armature together while preventing the iiow of fuel to the burner until the armature and electromagnet are retained in engagement with each other as the result of the energization of the electromagnet.

30. In combination, a valve seat, valve means cooperable therewith, an electromagnet movable into engagement with said valve means to pick up the valve means when the electromagnet is energized, means for retracting the electromagnet away from the valve seat and operable to move the valve means to open position with the movement of the electromagnet, and means for separating the valve means from said electromagnet and moving same into engagement with said valve seat upon deenergization of said electromagnet, the amount of separation of said valve means and electromagnet being such that the electromagnet is incapable ot moving said valve means away from said valve seat upon reenergization of said electromagnet.

31. In combination, a valve seat, valve means cooperable with said valve seat and provided with an armature portion, an electromagnet mounted for movement relative to said valve seat, means for energizing said electromagnet, means for separating the valve means irom the electromagnet and for moving said valve means into engagement with the valve seat upon deenergization of the electromagnet, the amount of separation between said electromagnet and valve means being sizilicient that the electromagnet is incapable of moving said valve means from said valve seat upon reenergisation oi said electromagnet, means for moving the electromagnet toward said valve means suiliciently to pick up the valve means when the electromasnet is and means for retracting the electromagnet away from the valve seat and operable to move the valve means with the electromagnet and to open position when the electromagnet is energized.

32. In combination, a valve seat. valve means cooperable with said valve seat and provided with an armature portion, an electrumasnet mounted for movement relative to said valve seat. means for energizing said electromasnet. means for separating the valve means from the electromagnet and for moving said valve means into t with the valve seat upon deenergization of the electromagnet, the amount oi separation between said electromagnet and valve means being suiiihcient that the electromagnet is incapable of moving said valve means from said valve seat upon reenergization of said electromagnet, means for moving the electromagnet toward said valve means suiilciently to pick up the valve means when the electromagnet is energized, means for retracting the electromagnet away from the valve seat and operable to move the valve means with the electromagnet and to open position when the electromagnet is energized, and a second valve means operated by the means for moving the electromagnet to position to pick up said iirst valve means.

33. In combination. a valve seat, a valve member cooperable with said valve seat, an armature device, an electromagnet device, both mounted for movement relative to said valve seat and one of said devices being connected to said valve member, means for energizing said electromagnet device, means for separating the armature device and the electromagnet device .to move said valve member into engagement with the valve seat upon deenergization of the electromagnet device, the amount of separation of said devices being sumcient to prevent their reengagement upon reenergization of said electromagnet device, means for moving one of said devices toward the other to position to pick up the other of said devices and therefore the valve member when the electromagnet is energized, and means for retracting said devices and said valve member away from the valve seat when the electromagnet device is energized.

34. In combination, a iiuid supply conduit, a valve means for controlling the supply of fluid through said conduit, means including an armature and a cooperating electromagnet operable to control said valve means, means to energize said electromagnet to hold the same and said amature in engagement, said valve means moving to a closed position and said armature and electromagnet separating such a distance upon deenergization of said electromasnet that said electromagnet is incapable of attracting said armature upon reenergization of said electromagnet, and means for reenggins said armature and electromagnet while maintaining said valve means in a closed position.

" 35. In combination, a main burner, a fuel supply line for said main burner, a pilot burner for said main burner, valve means for controlling the now of fuel to said main burner, means including an armature and a cooperating electro- A magnet operable to control said valve means, means including a device responsive to the temperature produced by said pilot burner to energize said electromagnet and maintain said armasaid pilot remains extinguished and including means for reengaging said amature and electromagnet while maintaining said valve means in its position shutting of! the supply of i'uel to said main burner.

. CLIFFORD HOTCHKISS. 

